I take in my grandparent's cars to Discount Tire all the time and they don't even look twice at me when I give my grandmother's phone number. Actually their Trailblazer is still in there under my great-aunt's name (who originally bought it). Wednesday I'm taking it in and having them warranty out the tires.
My Jeep is still there under my grandfather's name. No issues, no questions.
2015 Hyundai Sonata 2.4L 79k PU 5w30 & OEM
2000 Toyota Camry 2.2L 228k M1 AFE 0w30 & Wix
1996 Jeep Cherokee 4.0L 146k M1 HM 10w40 & Fram Ultra